Application of temperature gradient gel electrophoresis technique to monitor changes in the structure of the eukaryotic leaf-epiphytic community of <Emphasis Type="Italic">Posidonia oceanica</Emphasis>

Seagrass leaves have been recognized as a suitable substratum in shallow sedimentary environments for the establishment of epiphytic communities. Microscope-based identification of species has been traditionally used to monitor changes in the composition of the eukaryotic leaf-epiphytic community of the seagrass Posidonia oceanica (L.) Delile. Our main goal was to adapt the temperature gradient gel electrophoresis (TGGE) barcoding technique largely used in molecular microbial ecology studies to monitor changes in the composition of P. oceanica epiphytic community. This molecular technique has been successful for handling large amounts of samples in a fast and reproducible manner. To that end, we applied the TGGE technique to study the epiphytic community in two different seasons and compare the results with those provided by the classical microscope approach. The results obtained with both approaches were generally consistent. The complexity of the banding pattern produced by TGGE was mirrored by the taxa richness of the community described using the classical approach. The minimum number of P. oceanica shoots necessary to adequately represent the composition of the eukaryotic leaf-epiphytic community was of the same order of magnitude for both techniques. Partial gene sequences of some selected bands affiliated with sequences of zoo and phytoephytic taxa. Some of them were detected using microscopy. Our results showed that TGGE is an excellent approach for comparative macrobenthic community studies that need parallel treatment of many samples at a time. To the best of our knowledge, this is the first time in which molecular barcoding techniques have been applied to the comparison of eukaryotic epiphytic communities.     

Assessment of trace metals pollution in estuarine sediments using SEM-AVS and ERM?CERL predictions

In this paper a PSIAC-based multi-parameter fuzzy pattern recognition (MPFPR) model is proposed and applied for classifying and ranking the potential soil erosion (PSE). In this approach, standard value matrix is used to define the membership degrees of each catchment to each class and the feature values are used for alternative ranking. The characteristic of PSE for each class is expressed by linguistic variables. The proposed method is straightforward, easy to understand, very practical, and its results may easily be interpreted. To assess the performance of the model, the results of PSIAC MPFPR and original PSIAC method are interpreted and compared with the observed data. It is shown that the proposed approach reflects the fuzzy nature of the soil erosion more efficiently and is quite robust for application in real world cases.     

Highly concentrated phenolic wastewater treatment by the photo-Fenton reaction, mechanism study by FTIR-ATR

Phenol degradation by Photo-Fenton reaction has been studied in highly concentrated wastewaters and most intermediate species have been identified by Fourier Transform IR-Spectroscopy with ATR device. During the photodegradation of highly concentrated phenol solutions, the formation of dissolved and precipitate tannin has been observed. The possibility of a Fe3+-Pyrogallol complex formation, previous to the tannin formation, has been proposed too. The complex formation involving Fe3+ ions could be related to the observed Photo-Fenton activity decrease. Tannin formation inhibits the complete mineralization of phenol because *OH radicals attack will produce further condensation steps and the polymer size increase. This fact limits the applicability of the process for highly concentrated phenolic wastes mineralization. However, the tannin precipitation allows its separation from the solution by conventional filtration, and reduction of the corresponding dissolved organic carbon. These observations have been proved from the identification of primary degradation products, catechol and hydroquinone. Catechol is considered to be the first step for the formation of tannins. Degradation process for phenol, catechol and hydroquinone have been monitored by total organic carbon (TOC) measurements along the reaction time span. From these results, a global mechanism for the Photo-Fenton degradation of phenol is proposed.     

The social dimension as a driver of sustainable development: the case of family farms in southeast Spain

The social pillar has often been treated as an ‘add on’ in sustainable development studies, and analyses of its ‘proactivity’ in economic, environmental, and social transformations to sustainability outcomes are scant. The present paper looks at the social dimension as a key driver of sustainable development. Social factors in the farming system in southeast Spain are analyzed to show how family farms and their networks can integrate socio-economic and eco-social goals, promoting the generation of synergies and trade-offs between the dimensions of sustainability. This study contributes to existing debate on the role of family farms in the framework of European rural development.     

Determination of Cu and Ni incorporation ratios in Portland cement clinker

Cu and Ni are metals found in galvanic sludges; these sludges are considered hazardous due to their heavy metal content. The main objective of this work is to determine the incorporation amount of Cu and Ni in Portland clinker when a galvanic sludge containing these metals is added to the clinker raw-material. The influence of this addition on the clinkering reactions is evaluated as well as the possibility of co-incinerating galvanic sludges containing Cu and Ni in rotary cement kilns. This study also characterizes the galvanic sludge. Samples were prepared by additions from 0.25 to 5 wt.% of a galvanic sludge to an industrial clinker raw-material. The clinkering process was simulated in a laboratory device. The following techniques were applied to characterize the raw materials and the products of the tests: chemical analysis, differential thermal analysis (DTA) and thermogravimetric analysis (TG). Leaching tests were performed in the produced clinker samples in order to verify the incorporation of the studied metals in the clinker structure. The results led to the conclusion that additions of up to 2 wt.% of a galvanic sludge containing 2.4 wt.%Cu and 1.2 wt.% Ni to clinker raw-material do not affect the clinkering reactions and that these metals are totally incorporated into the clinker.     

Design and Application of Multi-layer Starch-Latex Blends as Phosphorous Delivery System

Journal of Polymers and the Environment - The search for highly productive agriculture has considerably increased the use of fertilizers, becoming a worrying source of environmental and health...     

Performance of compostable baby used diapers in the composting process with the organic fraction of municipal solid waste

In modern societies, disposable diapers constitute a significant percentage of municipal solid wastes. They have been traditionally landfilled or incinerated as only limited recycling processes are being implemented in some parts of Europe. With the implementation of separated collection systems for the organic fraction of municipal solid wastes (OFMSWs) and the need to preserve the environment, compostable diapers have appeared in the market to avoid the main environmental impacts associated to non-biodegradable disposable diapers. In this study, a full-scale composting of door-to-door collected OFMSW with a 3% (w/w) of compostable diapers has also been carried out. Previously, lab-scale experiments confirmed that almost 50% of carbon of compostable diapers is emitted as CO₂ under aerobic controlled conditions. The results obtained at full-scale demonstrate that both the composting process and the final end product (compost) are not altered by the presence of compostable diapers in crucial aspects such as pathogenic content, stability and elemental composition (including nutrients and heavy metals). The main conclusion of this study is that the collection of the OFMSW with compostable diapers can be a new way to transform this waste into high-quality compost.     

Planning waste cooking oil collection systems

This research has been motivated by a real-life problem of a waste cooking oil collection system characterized by the existence of multiple depots with an outsourced vehicle fleet, where the collection routes have to be plan. The routing problem addressed allows open routes between depots, i.e., all routes start at one depot but can end at the same or at a different one, depending on what minimizes the objective function considered. Such problem is referred as a Multi-Depot Vehicle Routing Problem with Mixed Closed and Open Inter-Depot Routes and is, in this paper, modeled through a mixed integer linear programming (MILP) formulation where capacity and duration constraints are taken into account. The model developed is applied to the real case study providing, as final results, the vehicle routes planning where a decrease of 13% on mileage and 11% on fleet hiring cost are achieved, when comparing with the current company solution.     

Testosterone stress does not increase asymmetry of a hormonally mediated sexual ornament in a lizard

The theory that fluctuating asymmetry is sensitive to both environmental and genetic stress is gaining acceptance among evolutionary biologists. Most empirical work has focused on ornamental traits on the assumption that they are more susceptible to stress. In tegumentary coloration is a common ornament in nature, and frequently has a hormonal basis. Earlier studies in the lizard Psammodromus algirus indicate that testosterone induces the development of head nuptial coloration in large males and, at the same time, produces an increase of the ectoparasite load and higher mortality. Hence, the manipulation of testosterone levels may be a way to increase ornament expression and simultaneously create conditions that may make symmetrical development difficult. This positive covariation between character size and symmetry is opposite to that expected in theory for sexually selected traits, so the predicted elevation of asymmetry due to the treatment cannot be confounded by any intrinsic association between symmetry and character size. We firstly consider the effect that testosterone supplementation has on two variables that reflect the symmetry of bilateral throat nuptial coloration in large P. algirus males. Also, we examine whether ornament symmetry is positively associated with reproductive success, a prediction of theory of sexually selected symmetry. Testosterone treatment did not increase the fluctuating asymmetry of throat coloration. Size asymmetry increased with character size in individuals with a fragmented colour pattern, but changed suddenly to a highly symmetric pattern in individuals with non-fragmented coloration. Mirror asymmetry decreased steadily with character size. These results suggest that the development of coloration on both sides of the throat midline follows a random pattern. Asymmetry did not correlate with variables that estimated reproductive success, suggesting that asymmetry is not affected by physiological stress and that this trait is not a sexually selected signal in P. algirus. Received: 1 July 1996 / Accepted after revision: 4 May 1997